In a vehicle electric motor drive system, high frequency switching of a power inverter may introduce electromagnetic interference (EMI) to other onboard electronic devices. Furthermore, recent increased availability of silicon carbide (SiC) and gallium nitride (GaN) devices has enabled power inverters to operate at higher switching frequencies, which can increase the amount of EMI. The generated EMI noise currents, referred to as conducted EMI noise, may travel along the input and output power lines and cause interference with other electronic systems. To avoid interference between different systems, the EMI noise emissions from power inverters and/or power converters may be controlled to comply with certain electromagnetic compatibility (EMC) standards, which are specified by automotive manufactures, international standards organizations, and/or government entities.
EMI filters may be included with, or otherwise associated with, power converters and/or power inverters to provide attenuation for the conducted EMI noise. Usually, EMI filters are positioned in the input part of power converters/inverters, but in some applications, filters may be employed for both input and output locations. While EMI filters can attenuate the conducted EMI noise to meet the EMC standards, EMI filters may bring additional weight and volume, as well as increasing the cost of power converters/inverters. However, it can be difficult to design a suitable EMI filter that is light-weight, compact, low-cost, and still able to filter out undesirable EMI noise in a manner sufficient to meet EMC requirements. Conventional design techniques may involve a great deal of trial and error, often requiring multiple iterations for tuning filter component values, which can be inefficient and time-consuming.